The Diabetic Foot Ulcer Scale (DFS): A quality of life instrument for use in clinical trials

Abstract

The diabetic foot ulcer scale (DFS) questionnaire is a specific instrument designed to assess the impact of foot ulcers and their treatment on quality of life in people with diabetes. Based on the results of semi-structured interviews and focus-group discussions with foot ulcer patients and caregivers, the DFS consists of 58 items grouped into 11 domains: leisure, physical health, daily activities, emotions, noncompliance, family, friends, positive attitude, treatment, satisfaction, and financial. Two studies have been conducted to develop and validate the DFS. The first of these included 173 patients with diabetes and current foot ulcers (n = 48), healed foot ulcers (n = 54), or no history of foot ulcers (n = 71). A generic measure of health status, the SF-36, was used to test construct validity. The DFS had good internal consistency. Significant differences between patients with current ulcers and those with healed ulcers were observed in the mean scores for the leisure, emotions, and financial domains (p < 0.05). Marked differences were also observed in physical health, daily activities, and friends domains, indicating that the DFS is able to discriminate patients with healed ulcers from those with current ulcers. The DFS was further evaluated in a relevant clinical setting (n = 288); confirmatory factor analysis confirmed the hypothesised factor structure of the DFS, but with slight suggestions for improved scaling. The DFS scales also demonstrated adequate test-retest reliability and sensitivity to change in wound status over time, indicating its appropriateness for use in clinical trials. Copyright © 2002 John Wiley & Sons, Ltd.